U.S. patent application number 13/994753 was filed with the patent office on 2014-10-09 for piston pump having a holder.
This patent application is currently assigned to Robert Bosch GmbH. The applicant listed for this patent is Oliver Gaertner, Daniel Gosse, Heiko Jahn, Marc Zimmermann. Invention is credited to Oliver Gaertner, Daniel Gosse, Heiko Jahn, Marc Zimmermann.
Application Number | 20140301876 13/994753 |
Document ID | / |
Family ID | 44863027 |
Filed Date | 2014-10-09 |
United States Patent
Application |
20140301876 |
Kind Code |
A1 |
Gaertner; Oliver ; et
al. |
October 9, 2014 |
PISTON PUMP HAVING A HOLDER
Abstract
A piston pump, in particular for a hydraulic assembly of an
electronically controllable vehicle brake system, includes a
cylinder element that has a pressure chamber with an outlet formed
on the inside. The piston pump further includes an
outlet-restricting element held on the outside of the cylinder
element on a component by a first holder.
Inventors: |
Gaertner; Oliver; (Abstatt,
DE) ; Jahn; Heiko; (Tamm, DE) ; Zimmermann;
Marc; (Sonthofen, DE) ; Gosse; Daniel;
(Berlin, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Gaertner; Oliver
Jahn; Heiko
Zimmermann; Marc
Gosse; Daniel |
Abstatt
Tamm
Sonthofen
Berlin |
|
DE
DE
DE
DE |
|
|
Assignee: |
Robert Bosch GmbH
Stuttgart
DE
|
Family ID: |
44863027 |
Appl. No.: |
13/994753 |
Filed: |
October 25, 2011 |
PCT Filed: |
October 25, 2011 |
PCT NO: |
PCT/EP2011/068639 |
371 Date: |
October 28, 2013 |
Current U.S.
Class: |
417/540 ;
417/437; 417/559 |
Current CPC
Class: |
F04B 11/0091 20130101;
B60T 8/4031 20130101; B60T 8/4068 20130101; F04B 53/162 20130101;
F04B 39/125 20130101; F04B 49/22 20130101; F04B 53/007 20130101;
F04B 1/0421 20130101; F04B 53/001 20130101 |
Class at
Publication: |
417/540 ;
417/437; 417/559 |
International
Class: |
F04B 49/22 20060101
F04B049/22; F04B 53/00 20060101 F04B053/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 17, 2010 |
DE |
102010063322.4 |
Claims
1. A piston pump, comprising: a cylinder element forming a delivery
chamber with an outlet on an inside of the cylinder element; and an
outlet-restricting element mounted on a component by a first mount
on an outside of the cylinder element.
2. The piston pump as claimed in claim 1, wherein the component is
positioned bearing against the cylinder element.
3. The piston pump as claimed in claim 1, wherein the component is
of substantially plate-shaped design.
4. The piston pump as claimed in claim 1, wherein the
outlet-restricting element is designed as a restrictor plate.
5. The piston pump as claimed in claim 1, wherein the component
comprises a second mount configured for a valve spring of an outlet
valve.
6. The piston pump as claimed in claim 5, wherein the valve spring
is embodied as a leaf spring or spiral spring.
7. The piston pump as claimed in claim 1, wherein the first mount
of the component comprises a step configured to pre-tension the
outlet-restricting element.
8. The piston pump as claimed in claim 1, wherein the component
defines spaced openings.
9. The piston pump as claimed in claim 1, wherein the component is
held by a closure element that forms a space for a damper.
10. The piston pump as claimed in claim 1, wherein the component is
formed as an injection-molded part, a turned metal part, or as a
cold-formed part.
11. The piston pump as claimed in claim 1, wherein the piston pump
is for a hydraulic assembly of an electronically controlled vehicle
brake system.
12. The piston pump as claimed in claim 8, wherein the openings are
spaced in the first mount.
Description
STATE OF THE ART
[0001] The invention relates to a piston pump, which is intended,
in particular, for a vehicle hydraulic brake system, having a
cylinder element, inside which a delivery chamber with an outlet is
formed.
[0002] Known piston pumps comprise a cylinder element, in which a
delivery chamber is formed. A piston is guided so that it is
axially displaceable in the delivery chamber. The piston can be
driven to perform a reciprocating stroke movement in an axial
direction, which causes fluid to be delivered in a manner known in
the art. In order to prevent noise-generating pressure pulses, a
damping chamber and a restrictor, which are both arranged outside
the cylinder element and often even separately from the piston
pump, are usually hydraulically connected to the outlet side of
such piston pumps.
[0003] Such a piston pump is disclosed in DE 103 14 979 B3. In
order to prevent noise-generating pressure pulses in the connected
hydraulic system, the known piston pump comprises a restrictor,
connected downstream of the fluid outlet for damping purposes. Here
the restrictor comprises a primary hydraulic filter. The fluid
outlet is guided along at least a portion of the circumferential
surface of a liner and in the area of this portion the filter and
the restrictor are formed in one piece on the circumferential
surface of the liner.
DISCLOSURE OF THE INVENTION
[0004] According to the invention a piston pump is created, in
particular for a hydraulic assembly of an electronically controlled
vehicle brake system, having a cylinder element, inside which a
delivery chamber with an outlet is formed. On the cylinder element
an outlet-restricting element is mounted on a component by means of
a first mount. In other words a component having a first mount for
an outlet-restricting element is arranged on the cylinder element
according to the invention. This outlet-restricting element may
more preferably be a restrictor.
[0005] In an advantageous development of the invention the
restrictor is embodied as a restrictor plate. The first mount, in
which the restrictor plate is then accommodated, may have a bearing
surface for this purpose. The restrictor plate can thereby be
subjected to defined pre-tensioning. The restrictor plate may also
be integrated into this first mount according to the invention.
Such a first mount is capable of achieving a very precise opening
pressure of the restrictor.
[0006] The restrictor itself is connected to the hydraulic outlet
side of an outlet valve of the piston pump, that is to say
downstream of the outlet valve of the piston pump in the direction
of flow. The restrictor may be arranged in a pump bore or in an
outlet duct in the pump housing, and according to the invention is
held in the first mount. The restrictor serves for damping pressure
pulses of the fluid delivered by the piston pump, which the piston
pump induces due to its pulsating mode of delivery.
[0007] In addition a second mount for a spring is also preferably
arranged or integrated in the component having the first mount for
the outlet-restricting element. In an advantageous development this
spring is the outlet valve spring for an outlet valve closing
member. The spring rests on the second mount in the component. For
this purpose the second mount may comprise a bearing surface. Here
the components of the outlet valve of the piston pump, comprising
the outlet valve closing member and the spring, are supported by
the second mount.
[0008] In an alternative development the spring is integrated into
the second mount. In this case the spring may be caulked into the
second mount. The form of the mount varies according to the design
of the spring. If the spring is a coil spring, the mount comprises
a cup-shaped seat for the coil spring. If the spring is a leaf
spring or spiral spring, the seat is of shallow design.
[0009] In addition a third mount for a hydraulic damper is
preferably arranged or integrated into the component.
[0010] In this case the fluid delivered preferably first flows
through an opening of the outlet valve into a damping chamber. The
outflow then ensues via further, defined openings on the component
according to the invention onto said restrictor plate. These
openings may be designed with various shapes, in particular
circular or slit-shaped. The restrictor plate sags due to the
incident flow and the pressure differential, and the fluid can flow
out via the further, defined openings. Here, at the same time, the
damping volume is sealed off from the outlet, therefore giving a
forced flow through the restrictor.
[0011] The damper forms a hydraulic capacity, which likewise has a
forced flow passing through it and thereby exhibits an optimized
response, because the restrictor forms a hydraulic resistance for
the fluid on the outlet side.
[0012] An installation space for a hydraulic accumulator is also
preferably provided in the component according to the invention.
The accumulator may form a part of said hydraulic capacity.
[0013] Spacers in the form of thin feet to compensate for
tolerances of the installation space of the component and to form
the outlet bore may optionally be arranged downstream of the
restrictor.
[0014] The component together with at least the one mount is
preferably formed as an injection molded part or as a turned metal
part or as a cold-formed part.
[0015] The design of the piston pump according to the invention
having the component with the first mount for the
outlet-restricting element and the further advantageous mounts,
which are arranged in this component or integrated into this
component, affords the advantage that multiple functions are
accommodated in just one component. Tolerances between the
functions can be minimized through a correspondingly precise
forming of this one single component.
[0016] The component serves, in particular, for the hydraulic
connection between the outlet valve, which constitutes the
separation from the delivery chamber, and an outlet bore. Here this
hydraulic connection between the outlet valve and the outlet bore
may, at no significant additional cost, at the same time have a
compressible volume.
[0017] The piston pump according to the invention in particular
comprises a pump cylinder, which is accommodated in a hydraulic
unit. The pump cylinder forms a cylinder element within the meaning
of the invention and as delivery chamber comprises a cylindrical
recess, in which a piston is guided so that it is axial
displaceable.
[0018] The piston pump according to the invention is intended, in
particular, as a pump in a brake system of a vehicle and is used
for controlling the pressure in wheel brake cylinders. Such brake
systems are commonly known to include wheel slip control (ABS or
ASR), a traction control system (TCS), a brake system serving as a
steering aid (FDR), an electro-hydraulic brake system (EHB) and/or
an electronic stability program (ESP). In such brake systems the
pump serves for returning brake fluid from wheel brake cylinders
into a brake master cylinder and/or for delivering brake fluid from
a reservoir into wheel brake cylinders.
[0019] Exemplary embodiments of the solution according to the
invention are explained in more detail below with reference to the
schematic drawings attached, of which:
[0020] FIG. 1 shows a longitudinal section of a piston pump with a
first exemplary embodiment of a component according to the
invention having a seat for a coil spring,
[0021] FIG. 2 shows a longitudinal section of a piston pump with a
second exemplary embodiment of a component according to the
invention having a seat for a spiral spring,
[0022] FIG. 3 shows an oblique top view of the component according
to FIG. 1,
[0023] FIG. 4 shows the section IV-IV in FIG. 3,
[0024] FIG. 5 shows and oblique view of the component according to
FIG. 1 from below,
[0025] FIG. 6 shows a view according to FIG. 5 with
outlet-restricting element,
[0026] FIG. 7 shows an oblique top view of a variant of the
component according to FIG. 1 and
[0027] FIG. 8 shows the section VIII-VIII in FIG. 7.
[0028] The piston pump 10 is represented in FIG. 1. The piston pump
10 comprises a piston 12, which is capable of a reciprocating
movement its in axial direction. This is done by means of an
eccentric drive (not shown). The piston 12 comprises an axial bore
14 and multiple radial bores 16. A guide element 18, which has a
passage opening 20 and which guides the piston 12 in a cylinder
element 22, is arranged on the piston 12. The cylinder element 22
is formed with a substantially tubular shape in a pump housing 11.
An inlet valve 24 is arranged at the end of the guide element 18
remote from the piston 12. The inlet valve 24 comprises a cage 26,
a return spring 28 and a closing member in the form of a plate 30.
The cage 26 is fixed to the guide element 16. The plate 30 closes
and opens the passage opening 20 in the guide element 18. The inlet
valve 24 is thereby arranged inside the cylinder element 22 in a
delivery chamber 32, in which furthermore a piston return spring 34
is also arranged.
[0029] In addition, the piston pump 10 comprises an outlet valve
36, which is arranged on the end face of the cylinder element 22
remote from the piston 12. The outlet valve 36 comprises a valve
member 39, which is pressed against a valve seat 41 formed in this
end face by a valve spring 62 in the form of a spiral spring.
[0030] A component 38 bearing on the cylinder element 22 and having
a first mount 40 in the form of a perforated annular disk for at
least one outlet-restricting element 42 is arranged on the side of
the end face remote from the delivery chamber 32. The
outlet-restricting element 42 is designed as a restrictor
plate.
[0031] In addition, a second mount 44 for supporting the valve
spring 62 of the outlet valve 36 is formed or integrated on the
component 38. The second mount 44 comprises an annular support or
bearing surface for the valve spring 62. The valve spring 62 may
optionally also be caulked into the second mount 44. The mount 44
can easily be adapted to the shape of the valve spring 62 to be
used. For the valve spring 62, here designed as a coil spring, the
mount 44 is of cup-shaped design.
[0032] An additional or further space 48 for the installation of a
hydraulic accumulator (not illustrated further) is provided axially
behind the component 38 in a cap-shaped closure element 46
adjoining the cylinder element 22.
[0033] The component 38 is formed as an injection-molded part, a
turned metal part or a cold-formed part.
[0034] FIG. 2 represents another variant of the piston pump 10
according to FIG. 1.
[0035] In this variant the second mount 44 is designed as a
comparatively shallow, substantially disk-shaped seat for a valve
spring 62 embodied as a leaf spring or spiral spring.
[0036] FIGS. 3 to 5 show the component 38 with its mount 40 in the
form of a cup-shaped seat and its mount 44 in the shape of an
annular disk angled at the outer edge.
[0037] A central opening 54 allowing the fluid coming from the
valve body 39 to pass through to the rear side of the component 38
is provided on the cupped base of the mount 40. Openings 52,
through which the fluid can flow back out from the rear side of the
component 38 to the front side thereof, are arranged spaced at
regular intervals in a circle on the annular disk of the mount 44.
Here the fluid must cause the outlet-restricting element in the
form of a restrictor plate, situated in front of these openings, to
pivot, so as to allow it to escape on the front side through the
openings 52. Six such openings 52 are provided here.
[0038] Outflow openings 56 in the form of depressions or recesses
of the edge and likewise spaced at regular intervals are formed at
the angled edge of the annular disk of the mount 44. Through these
outflow openings 56, fluid can be discharged downstream of the
outlet-restricting element 42 in the direction of flow into a
substantially radial outlet opening 37, which is formed in the pump
housing 11.
[0039] FIG. 6 represents the outlet-restricting element 44 in the
form of a deflectable restrictor plate, enclosed by the mount 44 on
the component 38, added to the component 38.
[0040] FIGS. 7 and 8 show a variant of the component 38, in which
the openings 52 are designed as radially oriented slits. Here the
slits as depressions also extend through the cup-shaped shoulder
for the mount 40 and through the annular plate for the mount
44.
[0041] Such a piston pump 10 functions as follows:
[0042] In a suction phase of the piston pump 10 the outlet valve 36
is closed and the inlet valve 24 is opened. Fluid is thereby
carried through the fluid feed line 17, towards and through a
filter element 19, the radial bores 16, the axial bore 14 and the
longitudinal bore 20 of the guide element 18 to the inlet valve 24.
The fluid is drawn into the delivery chamber 32 through the opened
inlet valve 24. At the bottom dead center of the piston 12 the
direction of movement of the piston 12 changes, causing the inlet
valve 24 to close. The piston 12 now moves in the direction of the
outlet valve 36. In the process pressure builds up in the delivery
chamber 32, until the pressure therein is greater than the return
force of the valve spring 62 of the outlet valve 36.
[0043] On the side of the outlet valve 36 remote from the delivery
chamber 32 the outlet-restricting element 42 in the form of a
restrictor plate is arranged on its mount 40 in the component 38.
Here, on the inside of the angled edge of the mount 40, the
component 38 comprises a step 64, on which the restrictor plate
bears with its outer edge area and is thereby pre-tensioned in an
axial direction. Such pre-tensioning leads to a defined opening
pressure for the restrictor plate in front of the openings 52.
[0044] For this purpose the component 38 is secured in the pump
housing 11 with the outlet-restricting element 42 between the
cylinder element 22 and the closure element 46.
[0045] With the outlet valve 36 opened, the fluid flows through the
component 38 according to the invention, through its central
opening 54, then past the outlet-restricting element 42 back
through the openings 52, and then onwards into the outlet opening
37 acting as delivery line. In conducting the fluid past the
outlet-restricting element 42, the latter is deflected from its
substantially radially oriented position or extent in an axial
direction and thereby imposes a restricting and/or damping effect
on the fluid.
[0046] All features represented in the description, the following
claims and the drawings may be essential for the invention, both
individually and in any combination with one another.
* * * * *